Revert of Preliminary attempt to remove batch tracker

src/gpu/GrPathProcessor.cpp

 /*
 * Copyright 2013 Google Inc.
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */
 
 #include "GrPathProcessor.h"
 
 #include "gl/GrGLPathProcessor.h"
@@ skipping 39 matching lines @@
         return false;
     }
 
     const GrPathProcessor& other = that.cast<GrPathProcessor>();
     if (!this->viewMatrix().cheapEqualTo(other.viewMatrix())) {
         return false;
     }
 
     const PathBatchTracker& mine = m.cast<PathBatchTracker>();
     const PathBatchTracker& theirs = t.cast<PathBatchTracker>();
-    if (mine.fColor != theirs.fColor) {
-        return false;
-    }
-
-    if (mine.fUsesLocalCoords != theirs.fUsesLocalCoords) {
-        return false;
-    }
-
-    if (mine.fUsesLocalCoords && !this->localMatrix().cheapEqualTo(other.localMatrix())) {
-        return false;
-    }
-
-    return true;
+    return CanCombineLocalMatrices(*this, mine.fUsesLocalCoords,
+                                   that, theirs.fUsesLocalCoords) &&
+           CanCombineOutput(mine.fInputColorType, mine.fColor,
+                            theirs.fInputColorType, theirs.fColor) &&
+           CanCombineOutput(mine.fInputCoverageType, 0xff,
+                            theirs.fInputCoverageType, 0xff);
 }
 
 void GrPathProcessor::getGLProcessorKey(const GrBatchTracker& bt,
                                         const GrGLSLCaps& caps,
                                         GrProcessorKeyBuilder* b) const {
     GrGLPathProcessor::GenKey(*this, bt, caps, b);
 }
 
 GrGLPrimitiveProcessor* GrPathProcessor::createGLInstance(const GrBatchTracker& bt,
                                                           const GrGLSLCaps& caps) const {
     SkASSERT(caps.pathRenderingSupport());
     return SkNEW_ARGS(GrGLPathProcessor, (*this, bt));
 }